Refrigerating apparatus



Oct. 3, 1933. IN 1,928,695

' 'REFRIGERATING APPARATUS Original Filed Aug. 51, 1928 gmm Mum a Gummy Patented Oct. 3, 1933 omrso STATES I BEFRIGERATING APPARATUS Jesse G. King, Dayton, Ohio, assignor to Frigidaire Corporation, Dayton, Ohio, a corporation of Delaware Application August 31, 1928, Serial No. 303,263

Renewed October 21, 1932 8 Claims.

I This invention relates to refrigerating apparatus and particularly to soda fountains and similar devices in which various commodities of "different characters are. maintained at different tempera-- tures.

It is one of the objects of the invention to provide a simplified and economical refrigerating system particularly adapted to soda fountains.

Another object of the invention is to provide 1 an improved and simplified arrangement for maintaining a number of diiferent temperatures by means of a'single refrigerating system.

More specifically it is one of the objects of .the invention to operate a plurality of evaporat- 5 ing elements in series and to provide an improved andsimplifled means for controlling the amount of liquid refrigerant which enters successive evaporators of the series. v

Further objects and advantages of the present invention will be apparent from the following description, reference being had to theaccompany sdrawing, wherein a preferred form of the present invention is clearly shown.

In the drawing:

Fig. l is a diagram of a refrigerating system embodying the present invention; and I Fig. 2 is a vertical longitudinal section of a portion of a control device. a

It is usual to provide soda fountains with a compartment for maintaining ice cream at a temperature, for example, of 7 F. or less, a compartment for cooling and maintaining water on draft at a temperature between.35 and and a compartment commonly called a syrup rail for maintaining containers of fountain syrups, fruit juices and the like, at temperatures between 35 and I". 1

My inventionis concerned with an improved .arrangement" and method for maintaining the above mentioned compartments at their individual proper temperatures by means of a single refrigerating system or apparatus.

Referring to Fig. 1 anysultable soda fountain is provided with an' ice creamstorage compartment l1,'a water cooling compartment 12 and a syrup rail or, compartment 13 for holding syrup containers. Each of the compartments may be suitably insulated according to the temperature at I which it is to be maintained. A relatively. high pressure evaporator 16 is placed in the water compartment and a relatively low pressure evaporator 17 placed in theme cream compartment. Preferably the evaporator 17 is immersed in a non-freezing solution such as brine as is 55 usual in cases of this character, and the evapora-' tor 16 is immersed in fresh water, which may be either-the water to be cooled, or a water bath, in

which is immersed a heat exchanger such as 18,

through which the water to be cooled is circulated. These evaporators are preferably of the flooded type and each includes a header 20 forming a reservoir for-liquid refrigerant which is kept at a constant level therein under the control of a float 22, andrefrigerant circulating tubes or coils The evaporators are supplied with liquid refrigerant through liquid lines 26 and 27 connected in parallel to a condensing element generally denoted by 28 which also withdraws evaporated refrigerant from both said evaporatorsthrough a vapor conduit '29.

Refrigerant evaporated in the evaporator 16 is withdrawn through a conduit 30 which is ultimately connected to the conduit 29 and which is provided with any suitable pressure regulating shut-off valve 31, the'constructionof which may be, for example as is illustrated and described in the application of Ernest Dickey, Serial No. 753,048, ,filedDecember 1, 1924. This valve is opened by the pressure of refrigerant, in the evaporator 16 and automatically closes at some predetermined low pressure corresponding, for example, to 25 F. and thus prevents refrigeration of the evaporator below that temperature.-

The condensing element 28 includes any suit; able compressor 32 actuated by a motor 33' under 5 the control of .a switch 34 which is operated in response to the pressure existing in the vapor conduit 29. when the pressure existing in this condiiit is above that corresponding to a temperature of about 5 F. the switch closes to actuate the compressor and withdraw the refrigerant from the evaporator 17 until the pressure has been reducedton value corresponding to a predetermined low temperature, for example 6' FL Refrigerant is evaporated in and withdrawn from evaporator 16 only when the pressure regulating valve 31 is open. Preferably the valve is arranged to snap open at a pressure corresponding to about I 28 F., and to remain open until the pressure has been reduced to a value corresponding to an evaporator temperature of about 14 F. when the valve snaps closed. 4

This will cause a layer of ice to form about the evaporatorlfi, which may periodically increase and decrease in thickness in accordance with the cyclicallvariations in temperature of the evaporator and will serve to keep the circulating water at a more or less steady temperature of about 40.

The conduit 30 connecting the evaporator 16 and the exhaust conduit 29 includes a portion 35 forming an evaporator which is in thermal relation with the syrup rail. The connection of the conduit 30 to the header 20 of evaporator 18;is

' so arranged that liquid refrigerant is supplied from the header to the evaporator 35 along with the vapor withdrawn. One way of arranging this connection is illustrated herein for the sake of example. The header 20 of evaporator 16 is provided with the usual head or end plate 40, secured to the header in any suitable manner, as by bolts passing through holes 41. The head 40 is provided with an inlet 42 and outlet 43 for connection to valves 44 and 45 in the liquid and vapor lines' 27 and 30 respectively. Inside the head, and containing the 'liquid inlet passage'42 is a boss 46 having a-sma1l opening. 47 for the admission of liquid to the header. A tubular support 48 for the float 22 and a needlevalve 50 (controlled by the float) is-mounted on the boss 46, and is provided with a e 51 registering with the opening 47 and forming a guide for the valve 50.

A suction tube 52 extends from the outlet 43 into the header, terminating in a horizontal opening 53 above the noimal level of liquid in the header. The header normally contains liquid refrigerant to the level 54 and oil to the level 55. At the level 55 an oil drain hole 56 is pierced in the tube 52. This refrigerant vapor is withdrawn through the tube 52 from above the liquid level,

and oil may drain out of the header whenever it reaches the level 55. A small tube 57 connects with the passage 51 near the opening 47, and just back of the point of the valve 50. This tube terminates within the vapor tube 52. The tube 52 may have a constriction 5'8 at'the end of the small tube 57, so that when vapor is withdrawn through the tube 52, suction will be produced, drawing liquid refrigerant through the tube 57 into the 0 tube 52. However, in many cases sufiicient liquid will-flow through the tube 57 without the use of the constriction 53. This will be readily understood'when it is considered that liquid refrigerant in the inlet 42 is under relatively high pressure,

for example pounds per square inch, while the liquid in the header is under relatively low pressure, for example 9 pounds per square inch. Therefore whenever the fioat valve opens, liquid flows through the opening 47 and-into the pas- 50 sage 51 at high velocity. The body of liquid present in the passage 51 tends to stop this rapid fiow of liquid and to convert its velocity head into pressure head. This pressure-head is sufiicient to cause a certain amount of liquid to flow up through the tube'58 into tube 52. Therefore liquid refrigerant is drawn into the evaporator 35 along with the vapor, and is there evaporated, cooling the syrup rail.

' It may happen that more liquid may be supplied to the evaporator 35 at certain times than so, in' the water adjacent the point 61 where the warm water fiows' into the compartment. The trap prevents liquid from flowing 'sumtmsrdrlserant downdirectly-tothe.anditsheatexchange surface, in contact with the relatively evaporates and superheats any liquid refrigeranf'fiowing from: the 35. is at a temperatures! 25' F. or less, it is readily evaporated and superheated by the water which is at a temperature of 40 F.

or more.

The abovedescribed system provides a very simple and reliable method of cooling the syrup rail of a soda fountain and of controlling the amount of liquid refrigerant which is admitted to the syrup rail evaporator.

While the form of embodiment of the invention as herein disclosed, constitutes a preferred form, it is to be understood that otherforms might be adopted. all coming within the scopeof the claiins which follow.

' What is claimed follows:

1. A soda fountain comprising in combination an ice cream storage compartment, 9. water cooling compartment, a syrup compartment, an evaporator for cooling each of said compartments, the syrup compartment evaporator and water compartment evaporator being connected in series, a condensing element for supplying liquid refrigeriamt to the ice cream compartment evaporator and water compartment evaporator, and conduits for returning the evaporated refrigerant from the ice cream compartment evaporatorand from the syrup compartment evaporator, the conduit from the syrup compartment evaporator passing through the water cooling compartment.

2. A soda fountain comprising in combination an ice cream storage compartment, a compartment for cooling circulating ,water'including a water container, a syrup compartment, an evaporator for cooling each of said compartments, the water compartment evaporator being immersed in said container, a condensing element for supplying refrigerant to the evaporators and conduits for returning the evaporated refrigerant from the evaporators'to the condensing element, the conduit from the syrup compartment evaporator having a portion immersed in said container adiacent the point of entry of the circulating water. I

' 3. A soda fountain comprising in combination an ice cream storage compartment, a water cooling compartment, a syrup compartment, an evaporator for cooling each of saidcompartments, a condensing element for supplying refrigerant to the evaporators, and conduits for returning the evaporated refrigerant from the evaporators tothe condensing element, the conduit from the syrup compartment evaporator including a liquid trap disposed in the 'water' cooling compartment for evaporating liquid refriger ant fiowing from the syrup rail compartment.

4. Refrigerating'apparatus comprising in com-- bination a pair of compartments to be cooled, an evaporator in each 'of the compartments, said evaporators being connected in series and arranged to deliver liquid refrigerant from the first evaporator to the second, a condensing element for supplying liquid refrigerant to the first evaporator and a conduit connecting the outlet of the second evaporator to the intake of the condensing element, said conduit including a heat exchanger disposed in the compartment containing the first evaporator for evaporating liquid refrigerant passing from the second evaporator.

5. Refrigerating apparatus comprising in combination a pair of compartments to be cooled. an evaporator in each of the compartments, said evaporstors being connected in series and arranged to deliver liquid refrigerant from-the first evaporator to the second, the second evaporator being above the first. a" element for supplying liquid refrigerant to thsfirstevaporaalso having an evaporator disposed therein, a rer combination, a compartment having an evapofrigerant liquefying and circulating unit having a liquid refrigerant supply connection with the first named evaporator and'a gaseous refrigerant connection with the second named evaporator, means for maintaining a predetermined quantity of liquid refrigerant in said first named evaporator, a conduit extending from said first named compartment to said second named compartment and having one of its ends communicating with the first named evaporator above the level of liquid refrigerant therein and having its other end connected with said second named evaporator, refrigerant conveying means having one end thereof disposed below the level of liquid refrigerant in said first named evaporator and having'its other end extending above the level of liquid refrigerant, a Venturi device within a por-' tion of said conduit, the end of said refrigerant conveying means above the level of liquid refrigerant in said first named evaporator being associated with said Venturi device, and said Venturi device being rendered effective by operations of said refrigerant liquefying and circulating unit for transferring liquid refrigerant from said first named evaporator to said second named evaporator.

7. A refrigerating apparatus comprising in rator disposed therein, a second compartment also having an evaporator disposed therein and located above the evaporator in the first'na'med compartment, a refrigerant liquefying and circulating unit having a liquid refrigerant supply connection with the first named evaporator and a gaseous refrigerant connection with the second named evaporator, means'for maintaining a predetermined quantity of liquid refrigerant in said first named evaporator, a conduit extending from said first named compartment to said second named compartment and having one of its ends communicating with the first named evaporator above the level of liquid refrigerant therein and having its other end connected with said second named evaporator, refrigerant conveying means having one end thereof disposed below the level of liquid refrigerant in said first named evaporator and having its other end extending above the level of liquid refrigerant, a Venturi device within a portion of said conduit, the end of said refrigerant conveying means above the level of liquid refrigerant in said first named evaporator being associated with said Venturi device, and' said Venturi device being rendered effective by operations of said refrigerant liquefying and circulating unit for lifting liquid refrigerant from said first named evaporator to said second named evaporator.

' 8. A refrigerating apparatus comprising in combination, a compartment having an evaporator disposed therein, a second compartment also having an evaporator disposed therein and located above the evaporator in the first named compartment, a refrigerant liquefying and circulating unit having a liquid refrigerant supply connection with the first named evaporator and a gaseous refrigerant connection with the second namedievaporator, a fioat valve mechanism for maintaining a predetermined quantity of liquid refrigerant in said first named evaporator, a conduit extending from said first named compartment to said second named compartment and having one of its ends communicating with the first named evaporator above the level of liquid refrigerant therein and having its other end connected with said second named evaporator, refrigerant conveying means having one end thereof disposed below the level of liquid refrigerant in said first named evaporator and having its other end extending above the level of liquid re frigerant, a Venturi device within a portion of said conduit, the end of said refrigerant conveying means above the level of liquid refrigerant in said first named evaporator being associated with said Venturi device, and said Venturi device being rendered effective by operations of said refrigerant liquefying and circulating unit for lifting liquid refrigerant from the body thereof in said first named evaporator into said conduit through said refrigerant conveying means to cause the fiow of liquid'refrigerant to said second named evaporator.

' JESSE G. KING. 

